Like performance-enhancing drugs inflating apparent athletic achievements, several common social science practices contribute to the production of illusory results. In this article, we examine the processes that lead to illusory findings and describe their consequences. We borrow from an approach used increasingly by other disciplines--the norm of…

To begin statistical analysis, Bayesians quantify their confidence in modeling hypotheses with priors. A prior describes the probability of a certain modeling hypothesis apart from the data. Bayesians should be able to defend their choice of prior to a skeptical audience. Collaboration between evaluators and stakeholders could make their choices…

This article discusses comparisons of means using exploratory and confirmatory approaches. Three methods are discussed: hypothesis testing, model selection based on information criteria, and Bayesian model selection. Throughout the article, an example is used to illustrate and evaluate the two approaches and the three methods. We demonstrate that…

Although the primary responsibility rests with the authors of articles reporting nonsignificant results to demonstrate the worth of the results by discussing the power of the tests, consumers should be prepared to conduct their own power analyses. This article demonstrates the use of power analysis for the interpretation of nonsignificant…

Power is an indicator of the ability of a statistical analysis to detect a phenomenon that does in fact exist. The issue of power is crucial for social science research because sample size, effects, and relationships studied tend to be small and the power of a study relates directly to the size of the effect of interest and the sample size.…

The hypothesis is the device scientists use to translate questions, theories, or proposed explanations into a form amenable to empirical research. This edition of W. W. Charter's treatise on clear, conceptual definitions and precise operational hypotheses, which was originally developed to assist students in educational policy and management…

In the educational research literature alpha, the a priori level of significance, and p, the a posteriori probability of obtaining a test statistic of at least a certain value when the null hypothesis is true, are often confused. Explanations for this confusion are offered. Paradoxically, alpha retains a prominent place in textbook discussions of…

This paper provides researchers with a method of determining sample size for a given power level in the preparation of a single group exploratory repeated measure analysis. The rationale for determining sample size which takes into consideration the powers and assumptions of both the adjusted univariate and multivariate repeated measures tests is…

Using a Monte Carlo approach, comparison was made between traditional procedures and a multiple linear regression approach to test for differences between values of r sub 1 and r sub 2 when sample data were dependent and independent. For independent sample data, results from a z-test were compared to results from using multiple linear regression.…

An examination of methodological referencing patterns for actual physics, engineering, and sociology literature for the year 1983, using a Dunn planned comparison approach, indicates that physics differs from both engineering and sociology, while no difference was found between engineering and sociology. References are given in each sample…

This article compares three models that have been the foundation for approaches to the analysis of statistical significance in early childhood research--the Fisherian and the Neyman-Pearson models (both considered "classical" approaches), and the Bayesian model. The article concludes that all three models have a place in the analysis of research…

This article explains and illustrates the estimation of the power of statistical tests used to analyze data in early childhood special education research, and discusses advantages and disadvantages of various ways to increase power, such as using a directional alternate hypothesis or using a parametric, rather than nonparametric, statistical test.…

A growing controversy surrounds the strict interpretation of statistical significance tests in social research. Statistical significance tests fail in particular to provide estimates for the stability of research results. Methods that do provide such estimates are known as invariance or cross-validation procedures. Invariance analysis is largely…

Graduate students individually examined 34 photographs for an investigation of commonly perceived underlying visual dimensions. Similarity judgements between photographs were used for multidimensional scaling; subject interview data were used to describe meaningful visual concepts. Results indicate that pictures were grouped in clusters along…

This article offers five research criteria and their rationale to help researchers avoid problems and to help them improve research. Improving research should improve the quality of science teaching. The treatment of causal hypotheses is stressed. (Author/CW)